Sleep when no input is available while streaming

[lukasmalkmus]

Sleep on some loops when no inputs is available.

Closes #90.

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (main@53dd7df). Click here to learn what that means.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main      #98   +/-   ##
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  Coverage        ?   14.22%           
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  Files           ?        9           
  Lines           ?      506           
  Branches        ?        0           
=======================================
  Hits            ?       72           
  Misses          ?      418           
  Partials        ?       16           

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[ImLunaHey]

@lukasmalkmus is this PR still valid?

[lukasmalkmus]

Technically, yes. Apparently this got lost as no one else ever reported any issues. My idea was to test this branch against main. I couldn't imagine Go really uses up a lot of CPU when waiting on a select statement. By "test" I mean to run two long running jobs and monitor CPU usage.